Exposure to this substance that can attack lymphocytes – which can be found in the immune system of a person – has been proven through the study of the effect of the chemicals with Rhesus monkeys, a species of monkeys that are 93% genetically compatible with human beings. The study between the monkeys and PCBs concluded with the severely affected thymus gland of the monkey. The thymus gland is responsible for the development and production of necessary hormones for the body and is highly susceptible in childhood (as it is more active in the body in the years before puberty).

There are, however, other such side effects that are attributed to exposure to these hazardous substances such as neurological defects by way of hindering things like visual recognition and learning. Exposure can cause be responsible for the rise in blood pressure or serum cholesterol, among other adverse health-related side effects. The same study regarding PCBs has stated that children born to women who have worked in factories dealing with PCBs had several decreases relating to their weight and gestation.

The effects of PCBs are still felt as the company manufactured things like electrical equipment, food packaging, and paint, among many other things. These were not disposed of properly as a lot of the waste can still be found in large bodies of water, which not only causes severe environmental problems but it also contaminates the supply of food and water for people and animals alike.